2011-10-17_REPORT - C1996083 (3)

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September 29, 2011 Bowie Resources, LLC Attn: Bill Bear P.O. Box 483 Paonia, CO 81428 Inclinometers Bowie Gob Pile 2 Instrumentation Monitoring 3rd Qtr 2011.doc Project #05- 126 -GEO Page 1 of 4 Civil, Structural & Geotechnical Engineers 222 South Park Ave. ^ Montrose, CO 81401 Ph.: (970) 249 -6828 • FAX: (970) 249 -0945 RE: BOWIE COAL WASTE DISPOSAL AREA NO. 2 SUBJECT: SUMMARY OF INSTRUMENTATION MONITORING, 3rd QUARTER 2011 Dear Bill, Buckhorn Geotech, Inc. (BGI) has conducted on -going monitoring of inclinometers and vibrating wire piezometers previously installed at Coal Waste Disposal Area No. 2 (CWDA No. 2) for Bowie Resources, LLC (Bowie). In 2005, three inclinometers were installed to monitor movement of placed refuse and five vibrating wire piezometers were installed to monitor pore pressures developed within the coal refuse. Installation details of the instrumentation are presented by BGI (2006). Three additional vibrating wire piezometers were installed in June 2009. This letter summarizes instrumentation monitoring at CWDA No. 2 through March 16, 2011. Three inclinometers, designated BG05 -4, -5, and -7, were installed at CWDA No. 2 in August 2005. The inclinometers were installed through the coal refuse and approximately 20 feet into the native foundation soils. Locations of the inclinometers are presented in Table 1 and on the attached site plan. Baseline readings were taken on 8/10/05 and subsequent readings have generally been taken quarterly. Cumulative displacement curves with respect to the baseline readings are presented as an attachment to this letter for each inclinometer. Axis "A" reflects deformation with depth in the direction of anticipated movement, while Axis "B" is orthogonal to Axis A. During our site visit on September 22, 2011 to read the instruments, we noted that Inclinometers BG05 -4, and BG05 -05, which were unreadable during our June 2011 visit, had been repaired. Readings were therefore taken at inclinometers BG05 -04, 05 and 07 and are reported herein. Based on our latest readings, no definite indications of deep- seated instability of the gob are observed in the inclinometer monitoring data. As described in previous letters, displacements indicated on the plots for the upper ten feet of the inclinometers are attributed to placement of cover soil on the face of the waste bank in late 2006 /early 2007. Movement previously recorded in the B -axis of inclinometer BG05 -05 has not progressed since the December 2008